Physical Exam

During the physical exam, your doctor will look for signs of respiratory failure and its underlying cause.

Respiratory failure can cause shortness of breath, rapid breathing, and air hunger (feeling like you can't breathe in enough air). Using a stethoscope, your doctor can listen to your lungs for abnormal sounds, such as crackling.

Your doctor also may listen to your heart for signs of an arrhythmia (irregular heartbeat). An arrhythmia can occur if your heart doesn't get enough oxygen.

Respiratory failure also can cause extreme sleepiness and confusion, so your doctor might check how alert you are.

Diagnostic Tests

To check the oxygen and carbon dioxide levels in your blood, you may have:

Pulse oximetry. For this test, a small sensor is attached to your finger or ear. The sensor uses light to estimate how much oxygen is in your blood.

Arterial blood gas test. This test measures the oxygen and carbon dioxide levels in your blood. A blood sample is taken from an artery, usually in your wrist. The sample is then sent to a laboratory, where its oxygen and carbon dioxide levels are measured.

A low level of oxygen or a high level of carbon dioxide in the blood (or both) is a possible sign of respiratory failure.

Your doctor may recommend other tests, such as a chest x ray, to help find the underlying cause of respiratory failure. A chest x ray is a painless test that takes pictures of the structures inside your chest, such as your heart, lungs, and blood vessels.

If your doctor thinks that you have an arrhythmia as a result of respiratory failure, he or she may recommend an EKG (electrocardiogram). An EKG is a simple, painless test that detects and records the heart's electrical activity.

Clinical trials are
research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans.
To find clinical trials that are currently underway for Respiratory Failure, visit
www.clinicaltrials.gov.